1-(bromomethyl)-2,3-difluoro-4-methylbenzene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A flask containing tetrahydrofuran (2.0 mL) was charged with sodium amide (152 mg, 3.69 mmol; Aldrich) and chilled to 0° C. (4-Fluorophenyl)hydrazine hydrochloride (400 mg, 2.64 mmol; Aldrich) was added in portions. After 5 minutes, the solid had completely dissolved and the ice bath was removed. Stirring was continued for 1 hour, then the solution was chilled again in an ice bath and 1-(bromomethyl)-2,3-difluoro-4-methylbenzene (598 mg, 2.72 mmol; Aldrich) was added dropwise. After 30 minutes, the ice bath was removed and the reaction was heated to 50° C. overnight. The mixture was diluted with water (5 mL) and extracted with dichloromethane (2×10 mL). The combined organic extracts were dried over magnesium sulfate, filtered, and concentrated in vacuo to afford the title product which was carried on without further purification: LC/MS (DCI/NH3) m/z 250 (M+H−NH3)+. was added in portions the solid had completely dissolved the ice bath was removed was continued for 1 hour the solution was chilled again in an ice bath After 30 minutes the ice bath was removed The mixture was diluted with water (5 mL) extracted with dichloromethane (2×10 mL) The combined organic extracts were dried over magnesium sulfate filtered concentrated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 2,3-difluoro-4-methylbenzyl bromide (Matrix, 10.47 g) and N-hydroxyphthalimide (7.73 g) in DMF (100 ml) was added drop-wise triethylamine (Et3N) (7.3 ml) (DBU may be used as an alternative to Et3N). The red reaction mixture was stirred at room temperature for 2 hours. On addition of 1 M HClaq. a white precipitate formed, that was isolated by filtration and washed with water and dried in vacuo affording a phthalimide intermediate (12.55 g, white shiny material). This compound (6.07 g) was dissolved in dichloromethane and methyl-hydrazine (1.16 ml) was added drop-wise. The reaction mixture was stirred at room temperature for 30 min. and the solid material was removed by filtration. The filtrate was evaporated under reduced pressure and purified by chromatography on silica gel (EtOAc/petroleum ether as eluent) and gave the title amine as a clear colourless oil (3.34 g). Alternatively the phthalimide intermediate can be treated with hydrazine monohydrate (1.0 eq.) in refluxing ethanol for 2-3 hours and the title compound obtained as the hydrochloride salt by treatment with 4M HCl in dioxane as described above for preparation 14. HCl salt: 13C-NMR (DMSO-d6) δ 150.0, 146.8, 128.4, 126.2, 126.1, 120.3, 68.9, 13.9. Free amine: 13C-NMR (CDCl3) δ149.2, 149.3, 127.0, 125.4, 124.5, 124.0, 70.9, 14.3 The red reaction mixture On addition of 1 M HClaq a white precipitate formed that was isolated by filtration washed with water dried in vacuo